This study examines the determinants of patenting and co-patenting with companies by European universities. The analysis takes into account more than 400 universities from 17 countries over the period 2011–2018. We test several determinants of the commercial activity of universities such as prior patent activity, age, public or private nature of the institution, students enrolment (size), students per academic staff, non-academic staff per academic staff, publication per academic staff and funds structure. We estimate two-part model with zero-inflated negative binomial regression which estimate separately the impact of the determinant on the probability of patenting (count data) and probability of no patenting (excess zeros).The data comes from RISIS Patents merged with ETER database. Discussant: Rainer Frietsch, Fraunhofer ISI